Mae Sai weather in December

In December, Mae Sai sees average daytime highs of 26°C and overnight lows near 15°C, with 31 mm of rain across 4.4 wet days and about 10.8 hours of daylight. It is the 12th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 26°C through the month. The sky is clear or mostly clear about 62% of the time in December, and the air most often feels humid.

Daylight stretches from about 10 h 54 min at the start of December to 10 h 48 min by month's end. Set against the rest of the year, December is Mae Sai's 4th-clearest and 8th-windiest month. For the whole year in context, see Mae Sai's year-round climate.

Daytime high
26°
12th warmest
Overnight low
15°
3rd coldest
Rainfall
31 mm
4.4 wet days
Daylight
10 h 48 min
6:54 AM – 5:40 PM
Cloud cover
35%
4th clearest
Wind
4 km/h
8th windiest
Solar energy
4.04 kWh/m²
Travel score
7.9
out of 10

Mae Sai is subdistrict municipality in Chiang Rai province, Thailand.

Density
5,365/km²
people per km²

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 26°C through the month.

A typical December day in Mae Sai reaches about 26°C in the afternoon and slips back to 15°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 23°C and 29°C. Set against its neighbours, December runs about 2°C cooler than November and about 1°C cooler than January.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12716
22716
32716
42716
52716
62716
72716
82716
92716
102716
112715
122715
132615
142615
152615
162615
172615
182614
192614
202614
212614
222614
232614
242614
252614
262614
272614
282614
292614
302614
312614

How December really feels in Mae Sai

Once humidity and wind are folded in, December averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

December sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Mae Sai weather by month

How December compares with the rest of the year at a glance. December is the 12th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 14°253.410.97.9
Feb30° / 14°152.411.36.1
Mar33° / 17°395.111.94.2
Apr34° / 21°11210.712.53.2
May33° / 23°27721.3132.8
Jun32° / 24°34926.713.22.4
Jul31° / 24°45528.513.12.5
Aug31° / 24°42428.712.72.6
Sep31° / 23°28724.212.13.0
Oct30° / 22°13416.711.54.3
Nov29° / 18°476.5116.5
Dec26° / 15°314.410.87.9

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 62% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 17% of December, with mostly cloudy or overcast conditions the remaining 21%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17822
27822
37822
47723
57624
67624
77723
87723
97624
107624
117723
127723
137723
147822
157822
167822
177921
187921
198119
208119
218119
228218
238218
248317
258218
268218
278218
288119
298119
308119
318020

Chance of precipitation in December

Any precipitation

Mae Sai gets around 31 mm of rain over 4.4 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 14% and peaks near 17% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
117
217
317
417
517
617
717
817
916
1016
1115
1215
1314
1414
1513
1613
1712
1812
1912
2012
2112
2212
2312
2412
2512
2612
2713
2813
2913
3013
3114

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

Most of December feels humid — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, December lands in the humid band about 34% of days. Sticky, muggy-or-worse air turns up on roughly 20% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
161741325
261840315
361940314
472039304
572139294
682238294
782338283
882437273
992537263
10102636252
11112736242
12122836232
13132935212
14143034201
15153134191
16173233171
17183333161
18183432151
19193532130
20203631120
21203831110
22213930100
2321403090
2421412990
2520422980
2620432980
2719452980
2818452880
2917462880
3016472880
3115482890

Wind in December

Winds average 4 km/h in December.

Across December, daily wind ranges from about 4 km/h on the calmest days to 4 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm
314calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 10 h 54 min at the start of December to 10 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 6:45 AM to 7:00 AM, and sunset from 5:36 PM to 5:47 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
110.96:455:36
210.86:455:36
310.86:465:36
410.86:475:36
510.86:475:36
610.86:485:37
710.86:485:37
810.86:495:37
910.86:505:37
1010.86:505:38
1110.86:515:38
1210.86:515:38
1310.86:525:39
1410.86:535:39
1510.86:535:39
1610.86:545:40
1710.86:545:40
1810.86:555:41
1910.86:555:41
2010.86:565:41
2110.86:565:42
2210.86:575:42
2310.86:575:43
2410.86:585:43
2510.86:585:44
2610.86:585:44
2710.86:595:45
2810.86:595:45
2910.87:005:46
3010.87:005:46
3110.87:005:47

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 4.04 kWh/m².

For context, solar energy here swings from a low near 3.91 kWh/m² to a high of 6.25 kWh/m² in April across the year — December's 4.04 kWh/m² sits near the bottom.

012345151015202531
Solar energy (kWh/m²)Level
14.0Bright
24.0Bright
34.0Moderate
44.0Moderate
54.0Moderate
64.0Moderate
74.0Moderate
84.0Moderate
94.0Moderate
104.0Moderate
114.0Moderate
124.0Moderate
134.0Bright
144.0Bright
154.0Bright
164.0Bright
174.1Bright
184.1Bright
194.1Bright
204.1Bright
214.1Bright
224.1Bright
234.1Bright
244.1Bright
254.1Bright
264.1Bright
274.1Bright
284.1Bright
294.1Bright
304.1Bright
314.1Bright
Planning a trip in December

Hazard calendar for Mae Sai

In seasonPeak

None of Mae Sai's seasonal hazards are active in December. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Mae Sai's monsoon runs May–September, when most of the year's rain falls.

Monsoon
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is December a good time to visit Mae Sai?

Our two travel scores rate December for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

7.9
Sightseeing
1st-best month of the year
7.7
Beach & pool
3rd-best month of the year

December is one of the better times to visit Mae Sai for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Mae Sai in December

From December's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In December, Mae Sai sees daytime highs around 26°C and nights near 15°C. Worth packing: light clothes. About 4 days see rain.

light clothes

UV index in Mae Sai in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Mae Sai peaks around July 19 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 7 (high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highHighJul 19UV 13Dec 20UV 7
UV index (midday)Level
Jan7High
Feb9Very high
Mar9Very high
Apr10Very high
May11Extreme
Jun13Extreme
Jul13Extreme
Aug13Extreme
Sep11Extreme
Oct10Extreme
Nov8Very high
Dec7High

Air quality in Mae Sai in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Mae Sai is worst in April — around 156 µg/m³ PM2.5 (very unhealthy), about 12.0× the cleanest month (July, 13 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0306090120150180JanFebMarAprMayJunJulAugSepOctNovDecModerateUnhealthyModerateApr 11150 µg/m³Jul 2313 µg/m³
PM2.5 (µg/m³)Level
Jan23Moderate
Feb40Poor
Mar128Unhealthy
Apr156Very unhealthy
May37Poor
Jun15Moderate
Jul13Moderate
Aug13Moderate
Sep13Moderate
Oct14Moderate
Nov15Moderate
Dec19Moderate
Location & terrain

Where is Mae Sai?

Mae Sai sits at 20.4°N, 99.9°E, 437 m above sea level, in Thailand. The nearest listed city is Tachilek, 2.0 km away.

Möng YawngPhayao

Topography around Mae Sai

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Mae Sai.

Within 3 km, the terrain around Mae Sai has significant variations in elevation — a maximum elevation change of 398 m around an average of 464 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,235 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,977 m.

The land around Mae Sai is covered by trees (54%) and artificial surfaces (33%) within 3 km, trees (61%) and cropland (27%) within 16 km, and trees (81%) within 80 km.

3 km
398 m
16 km
1,235 m
80 km
1,977 m
treesgrasslandcroplandartificial surfaces
December weather nearby: Tachilek 2.0 km · Ban Khoan 24 km · Mae Chan 32 km · Chiang Rai 59 km · Ban Houakhoua 64 km · Möng Yawng 97 km · Kengtung 133 km · Phayao 138 km

Thailand travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B / C
230 V · 50 Hz
Prices
≈ 31% of US
price level, 2025
GDP per capita
$8,057
2025
Happiness
6.3 / 10
World Happiness, 2025
Homicide rate
4.8
per 100k, 2011
Road deaths
32.2
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Very low
EF EPI 402
Religion
Buddhist 93%Muslim 5%Christian 1%other 1%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Mae Sai (20.4335°, 99.8762°, elevation 437 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).